postgresql data accelerator.md

For the complete documentation index, see llms.txt. Markdown versions of documentation pages are available by appending .md to page URLs; this page is available as Markdown.

PostgreSQL Data Accelerator

To use PostgreSQL as Data Accelerator, specify postgres as the engine for acceleration.

datasets:
  - from: spice.ai:path.to.my_dataset
    name: my_dataset
    acceleration:
      engine: postgres

Configuration

The connection to PostgreSQL can be configured by providing the following params:

pg_host: The hostname of the PostgreSQL server.
pg_port: The port of the PostgreSQL server.
pg_db: The name of the database to connect to.
pg_user: The username to connect with.
pg_pass: The password to connect with. Use the secret replacement syntax to load the password from a secret store, e.g. ${secrets:my_pg_pass}.
pg_sslmode: Optional. Specifies the SSL/TLS behavior for the connection, supported values:
- verify-full: (default) This mode requires an SSL connection, a valid root certificate, and the server host name to match the one specified in the certificate.
- verify-ca: This mode requires a TLS connection and a valid root certificate.
- require: This mode requires a TLS connection.
- prefer: This mode will try to establish a secure TLS connection if possible, but will connect insecurely if the server does not support TLS.
- disable: This mode will not attempt to use a TLS connection, even if the server supports it.
pg_sslrootcert: Optional parameter specifying the path to a custom PEM certificate that the connector will trust.
connection_pool_size: Optional. The maximum number of connections to keep open in the connection pool. Default is 10.

Configuration params are provided either in the acceleration section of a dataset.

datasets:
  - from: spice.ai:path.to.my_dataset
    name: my_dataset
    acceleration:
      engine: postgres
      params:
        pg_host: my_db_host
        pg_port: 5432
        pg_db: my_database
        pg_user: my_user
        pg_pass: ${secrets:my_pg_pass}
        pg_sslmode: require

Arrow to PostgreSQL Type Mapping

The table below lists the supported Apache Arrow data types and their mappings to PostgreSQL types when stored

Arrow Type	sea_query ColumnType	PostgreSQL Type
`Int8`	`TinyInteger`	`smallint`
`Int16`	`SmallInteger`	`smallint`
`Int32`	`Integer`	`integer`
`Int64`	`BigInteger`	`bigint`
`UInt8`	`TinyUnsigned`	`smallint`
`UInt16`	`SmallUnsigned`	`smallint`
`UInt32`	`Unsigned`	`bigint`
`UInt64`	`BigUnsigned`	`numeric`
`Decimal128` / `Decimal256`	`Decimal`	`decimal`
`Float32`	`Float`	`real`
`Float64`	`Double`	`double precision`
`Utf8 / LargeUtf8`	`Text`	`text`
`Boolean`	`Boolean`	`bool`
`Binary / LargeBinary`	`VarBinary`	`bytea`
`FixedSizeBinary`	`Binary`	`bytea`
`Timestamp` (no Timezone)	`Timestamp`	`timestamp` without time zone
`Timestamp` (with Timezone)	`TimestampWithTimeZone`	`timestamp` with time zone
`Date32` / `Date64`	`Date`	`date`
`Time32` / `Time64`	`Time`	`time`
`Interval`	`Interval`	`interval`
`Duration`	`BigInteger`	`bigint`
`List` / `LargeList` / `FixedSizeList`	`Array`	`array`
`Struct`	`N/A`	`Composite` (Custom type)

LIMITATIONS

The Postgres federated queries may result in unexpected result types due to the difference in DataFusion and Postgres size increase rules. Please explicitly specify the expected output type of aggregation functions when writing query involving Postgres table in Spice. For example, rewrite SUM(int_col) into CAST (SUM(int_col) as BIGINT.